Douglas Isbell
Headquarters, Washington, DC June 29, 1999
(Phone: 202/358-1547)
Keith Koehler
Wallops Flight Facility, Wallops Island, VA
(Phone: 757/824-1579)
RELEASE: 99-75
SCIENTIFIC "FIREWORKS DISPLAY" SET FOR EAST COAST IN JULY
NASA will set off its own Independence Day fireworks during a
series of nighttime rocket launches from July 2 to 20, 1999. Designed
to study "space weather" -- the interaction of the solar wind with the
Earth's magnetic field and atmosphere -- the experiments will focus on
improving our understanding of electrically charged atoms at the edge of
space.
During the 19-day period, two suborbital rockets will be launched
on each of two nights between 9:30 p.m. and 4 a.m. EDT from the NASA
Goddard Space Flight Center's Wallops Flight Facility, Wallops Island,
VA.
Two of the experiment packages will release a chemical that will
form large glowing clouds in space. These luminescent milky-white
clouds should be visible to the naked eye for several hundred miles from
the launch site, encompassing the mid-Atlantic region and portions of
the northeastern and southeastern United States. The clouds should be
visible for 10 to 20 minutes to the southeast of the launch site at
about 70 degrees elevation (approximately three-quarters of the way
between the horizon and the point of the sky that appears to be directly
above an observer).
The chemical, trimethylaluminum, will be released in the ionosphere
between 43 and 96 miles (69 to 154 kilometers) altitude. The harmless
by-products will disperse across thousands of miles as they diffuse into
the upper atmosphere.
The experiments will take place in a region above the Earth that at
first appears to be empty and very quiet. In fact, the Earth's upper
atmosphere actually is bustling with activity. Here the solar wind (a
fast-moving stream of particles emanating from the Sun), the Sun's
magnetic field and Earth's magnetic field and atmosphere come together.
Their interactions can create disturbances just above Earth's lower
atmosphere.
These disturbances can affect radio, television and satellite
communications. By better understanding these interactions in the
ionosphere, scientists hope to gain information that will ultimately
help improve the reliability of radio and satellite communications.
The specific aim of these experiments is to explore metallic ion
layers (regions of electrically charged particles) that exist about 60
miles (100 kilometers) above the Earth and to understand how their
interactions with wind in the upper atmosphere create large electric
fields and turbulence. The metallic ion layers are formed by material
from meteors that have collided with the Earth's upper atmosphere.
Each mission will consist of a one-stage Black Brant V rocket and a
two-stage Taurus-Orion rocket. The Black Brant V, which will carry
instruments only, will be launched first. The Taurus-Orion, carrying
the chemical package, will be launched approximately three minutes
later.
The status of the launches can be found by calling the Wallops
Flight Facility launch status line at (757) 824-2050 or on the Wallops
web page at:
http://www.wff.nasa.gov
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